Anionic surfactants having multiple hydrophobic and hydrophilic groups

ABSTRACT

Mild and environmentally benign bis-alkylphenol alkoxylated gemini surfactants of the formula: ##STR1## wherein R independently represents alkali, R 1  independently represents hydrogen EO represents ethyleneoxy radicals alkyl, R 2  independently represents hydrogen, --SO 3  M, --P(O) (OM) 2 , --CH 2  COOM, --CH 2  CHOHCH 2  --SO 3  HM, wherein M represents hydrogen, alkyl or alkaline earth metal, ammonium or an organic base salt; R 3  represents alkylene of from one to about 10 carbon atoms or --C(O)--R 4  --C(O)-- wherein R 4  represents alkylene or aryl, and --O--R 5  --O-- wherein R 5  represents aliphatic or aromatic moieties with the proviso that when R 3  is alkylene, then R 2  is not hydrogen, and a and b are numbers ranging from one to about 100, with the proviso that when R 2  is hydrogen, b is not zero.

This application claims priority from U.S. provisional applicationserial No. 60/009,075, filed Dec. 21, 1995. This application is adivisional of application Ser. No. 08/777,706, filed Dec. 20, 1996, nowU.S. Pat. No. 5,710,121.

This invention relates to a novel group of anionic surfactants having atleast two hydrophobic moieties and at least two hydrophilic groups permolecule.

BACKGROUND OF THE INVENTION

Anionic surfactants carry a negative charge on the hydrophilic portion,usually in the form of a carboxylate, phosphate, sulfate or sulfonate.These surfactants find use in emulsion polymerization as well as inagricultural chemicals, personal care and household products, industrialand institutional cleaners. They function as emulsifiers, cleaners,wetting agents, foaming and frothing agents such as for shampoos, carwashes, carpet shampoos, hand dishwashing, latex foaming, oil recoveryand other industrial uses.

While surfactants generally have one hydrophilic group and onehydrophobic moiety, recently a group of compounds having two hydrophobicmoieties and two hydrophilic groups have been introduced. These havebecome known as "Gemini surfactants" in the literature (Chemtech, March1993, pp 30-33), and J. American Chemical Soc., 115, 10083-10090, (1993)and the references cited therein. Other surfactant compounds having twohydrophilic groups and two hydrophobic moieties have been disclosed butnot referred to as Gemini surfactants.

It is known to sulfate, phosphate and carboxylate surfactants throughfunctionalization of the hydroxyls.

However, secondary hydroxyl's undergo sulfation, phosphation orcarboxylation poorly, leading to undesired by-products and/or highlevels of acid or low product yields. The compounds of the inventioncontain primary hydroxyl groups which can be more efficientlyfunctionalized.

There is also a need for new and more effective and efficientsurfactants, as well as the need for mild surfactants which arebiologically compatible in an ecologically sensitive environment. A newclass of compounds has been developed which demonstrates improvedsurface-active properties that are further characterized as mild, andenvironmentally benign.

SUMMARY OF THE INVENTION

According to the invention, an improved class of anionic surfactantshave been provided comprising compounds of the formula: ##STR2## whereinR independently represents alkyl of from about 4 to about 20 carbonatoms, R₁ independently represents hydrogen and alkyl of from about 4 to20 carbon atoms; R₂ independently represents --SO₃ M, --P(O) (OM)₂,--CH₂ COOM,

--CH₂ CHOHCH₂ SO₃ M, wherein M is hydrogen, alkali metal such as sodium,potassium, ammonium or organic base salt; and R₃ represents alkylene offrom one to about 10 carbon preferably from about 1 to about 4 atoms or--C(O)--R₄ --C(O)-- wherein R₄ represents alkylene of from 1 to about 10carbon atoms and aryl, e.g. phenylene. R₃ also represents --O--R₅ --O--wherein R₅ represents aliphatic or aromatic moieties of from 1 to about10 carbon atoms. EO represents ethyleneoxy radicals, a is a number offrom 0 to about 100 preferably one from about 0 to about 30. Preferably,R₃ is alkylene and more preferably --CH₂. As used herein the terms"alkyl" or "alkylene" include straight as well as branched chains.

When compared to the corresponding conventional anionic surfactants, thenovel compounds of the present invention show two unexpected surfaceactive properties; unusually low critical micelle concentration (CMC)showing exceptional surfactant effectiveness and pC₂₀ values thatexhibit exceptional surfactant efficiency in aqueous media. Theseproperties are a measure of the tendency of the surfactant to formmicelles and adsorb at the interface respectfully, and consequently, toreduce surface tension.

Preferably, R is alkyl of from about 6 to about 10 carbon atoms, and R₁is preferably hydrogen. The organic base salts of the compounds of theinvention can be illustrated by monoethanolamine, diethanolamine,triethanolamine, triethylamine, trimethylamine, N-hydroxyethylmorpholine and the like.

More specifically, the compounds of the present invention comprise:##STR3## wherein R, R₁, R₂, R₄, a, and R₅ are as defined hereinbefore.R₃ represents alkylene, preferably methylene. It is noted that when R₂is hydrogen or capped according to procedures well known in the art forpreparing alkoxylated nonionic surfactants, the compounds are nonionicand are, although considered as included in the generic invention, theywould be claimable as separate and distinct species. Compounds which arenonalkoxylated have been found to be particularly effective in blendssuch as with silicone compounds.

The primary hydroxyl group of the nonionic surfactants of this inventioncan be readily phosphated, sulfonated or carboxylated by standardtechniques.

In addition to new compounds, the invention also discloses novelsynergistic compositions when the compounds of the invention are blendedwith other surfactants.

DETAILED DESCRIPTION OF THE INVENTION

The compounds of the invention can be prepared by a variety of syntheticroutes. The compounds of Formula II can be prepared by condensing amonoalkyl phenol with paraformaldehyde in the presence of an acidcatalyst such as acetic acid. The compounds of Formula III can besynthesized by a Lewis acid catalyzed reaction of an alkylphenol with adicarboxylic acid, e.g., terephthalic acid or succinic acid. Thecompounds of Formula IV can be synthesized by a base catalyzed reactionof an alkyldihydroxybenzene with a dibromide.

These products can be oxyalkylated by reacting the product with analkylene oxide according to known methods, preferably in the presence ofan alkaline catalyst. The free hydroxyl groups of the phenol or thealkoxylated derivative can then be sulfated, phosphated orcarboxymethylated using normal methods such as sulfation with sulfamicacid or chlorosulfonic acid or sulfur trioxide, or carboxymethylatedwith an acylating agent such as a chloroacetic acid.

For alkylation conditions and commonly used alkylating agents, seeAmphoteric Surfactants Vol. 12, Ed. B. R. Bluestein and C. L. Hilton,Surfactant Science Series 1982, pg. 17 and references cited therein, thedisclosures of which are incorporated herein by reference.

For sulfation and phosphation, the reaction product of theparaformadehyde and the phenol can be reacted with a sulfating orphosphating agent such as sulfur trioxide, sulfamic acid, chlorosulfonicacid or phosphoric anhydride to form the compounds of the invention(Sulfation techniques are discussed in Surfactant Science Series, Vol 7,Part 1, S. Shore & D. Berger, page 135, the disclosure of which isincorporated herein by reference. For phosphating review see SurfactantScience Series, Vol 7, Part II, E. Jungermann & H. Silbrtman, page 495,the disclosure of which is incorporated herein by reference.)

Since the surfactants of the invention exhibit an extremely low criticalmicelle concentration (CMC) as compared with conventional surface-activeagents because of the presence of two hydrophobic moieties and twohydrophilic groups in their molecule and since they are able to fullyreduce surface tension and are highly soluble in water, the surfactantsof the invention are extremely effective in aqueous solution at lowconcentrations. The surfactants of the invention can be used in anyamount needed for a particular application which can be easilydetermined by a skilled artisan without undue experimentation.

The surfactants of the invention can be used alone as the essentialhydrotrope component.

It has been unexpectedly found that blends of the compounds of theinvention with certain conventional well known anionic, nonionic,cationic and amphoteric surfactants provide synergistic effects inrelation to critical micelle concentration and surface tension reducingability.

Examples of the nonionic surfactants usable herein include fatty acidglycerine and polygycerine esters, sorbitan sucrose fatty acid esters,higher alcohol ethylene oxide adducts, polyoxyethylene alkyl and alkylallyl ethers, polyoxyethylene lanolin alcohol, glycerine andpolyoxyethylene glycerine fatty acid esters, polyoxyethylene propyleneglycol and sorbitol fatty acid esters, polyoxyethylene lanolin, castoroil or hardened castor oil derivatives, polyoxyethylene fatty acidamides, polyoxyethylene alkyl amines, an alkylpyrrolidone, glucamides,alkylpolyglucosides, mono- and dialkanol amides. Examples of the anionicsurfactants used herein include fatty acid soaps, ether carboxylic acidsand salts thereof, alkane sulfonate salts, α-olefin sulfonate salts,sulfonate salts of higher fatty acid esters, higher alcohol sulfateester or ether ester salts, higher alcohol phosphate ester and etherester salts, condensates of higher fatty acids and amino acids, andcollagen hydrolysate derivatives.

Examples of the cationic surfactants used herein includealkyltrimethylammonium salts, dialkyldimethylammonium salts,alkyldimethylbenzylammonium salts, alkylpyridinium salts,alkylisoquinolinium salts, benzethonium chloride, and acylamino acidtype cationic surfactants.

Examples of the amphoteric surfactants used herein include amino acid,betaine, sultaine, phosphobetaines, imidazoline type amphotericsurfactants, soybean phospholipid, and yolk lecithin.

Any of commonly used auxiliary additives such as inorganic salts such asGlauber salt and common salt, builders, humectants, solubilizing agents,UV absorbers, softeners, chelating agents, and viscosity modifiers maybe added to the surfactants of the invention or blends thereof withother surfactants as disclosed herein.

The anionic surfactants of the invention are extremely mild andnon-irritating to both eyes and skin and exhibit low toxicity; exhibitenhanced wetting speed, greater surface tension reduction, high foamingand foam stabilization properties, and excellent compatibility withother surfactants. The products of the invention are stable over a widepH range and are biodegradable. These properties make these surfactantsadaptable for use in products ranging from cosmetics to industrialapplications, such as for non-irritating shampoos, e.g., baby shampoos,body shampoos, bubble baths, bar soaps, bath gels, hair conditioninggels, lotions, skin creams, make up removal creams, liquid detergents,and other washing and cosmetic products that contact the skin. Thesurfactants of the invention can also find use as hard surface cleanersincluding cars, dishes, toilets, floors, and the like; laundrydetergents and soaps, metal working aids and the like.

It has also been unexpectedly found that the compounds of the inventionparticularly nonalkoxylated compounds are particularly useful in novelsuperwetting compositions containing an organosilicone compound(s) whichcan be represented by the general formula:

    MDyD'xM                                                    Formula V

wherein M represents Me₃ SiO/_(1/2) (represents Me₃ SiO or Me₃ Si asnecessary to form a chemically complete structure); D represents Me₂SiO; D' represents MeRSiO; Me equals CH₃ ; R equals C_(n) H_(2n) O(C₂ H₄O)_(a) (C₃ H₆ O)_(b) R'; y ranges from about 0 to 5, preferably zero; xranges from about 1 to 5, preferably 1; n ranges from about 2 to 4,preferably 3; a ranges from about 3 to 25, preferably 3 to 15; and branges from about 0 to 25, preferably 0 to 15; it being understood thatthe oxyalkylene groups may be random and/or block mixtures; and R' canbe hydrogen, an alkyl group having 1 to 4 carbon atoms, or an alkylester group wherein the alkyl group of the ester has 1 to 4 carbonatoms. Each R' can be same or different on any given molecule.Preferably, R' is hydrogen or a methyl group.

These organosilicone compounds can be represented by the followingexamples:

    (Me.sub.3 SiO).sub.2 Si(Me)CH.sub.2 CH.sub.2 CH.sub.2 (OCH.sub.2 CH.sub.2).sub.8 OH

    (Me.sub.3 SiO).sub.2 Si(Me)CH.sub.2 CH.sub.2 CH.sub.2 (OCH.sub.2 CH.sub.2).sub.8 OAc

    Me.sub.3 SiOSi(Me).sub.2 OSi(Me).sub.2 OSi(Me).sub.2 CH.sub.2 CH.sub.2 CH.sub.2 (OCH.sub.2 CH.sub.2).sub.8 OH

    (Me.sub.3 SiO).sub.2 Si(Me)CH.sub.2 CH.sub.2 CH.sub.2 (OCH.sub.2 CH.sub.2).sub.7.5 OMe

The most preferred organosilicone compound is represented by thefollowing formula:

    (Me.sub.3 SiO).sub.2 Si(Me)CH.sub.2 CH.sub.2 CH.sub.2 (OCH.sub.2 CH.sub.2).sub.7.5 OMe

also known as SILWET L-77.

This is more fully disclosed in copending U.S. patent application Ser.No. 08/576,749, of Gao, et al., filed on even date herewith the presentapplication, the entire disclosure of which is incorporated herein byreference.

Examples of the present invention are given below by way of illustrationand not by way of limitation. All parts and percents are by weightunless otherwise stated.

EXAMPLE I

Preparation of 2,2'methylenebis 4(1,1,3,3-tetramethylbutyl)phenol!.

Dissolve 4-(1,1,3,3-tetramethylbutyl phenol 724 g. 3.51 mole! in aminimum amount of xylene at room temperature in a three necked roundbottom flask. Paraformaldehyde (15 g. 0.5 mol) and glacial acetic acid(100 mL.) were added slowly to the solution under argon. Reactiontemperature was slowly raised to 135° C. (about 150° C. externaltemperature) as the solution was stirred vigorously. Water generatedduring the reaction was collected by Dean-Stark apparatus. Afterstirring 5 hours at 135° C., GC analysis indicated complete reaction.The reaction was stopped by distilling out all starting materials underreduced pressure at 150° C. The final pure product was obtained bywashing the crude product twice with hexane in the flask. The whitesolid product was collected by filtration. Melting point of the finalcompound is 153° C. The NMR agreed with the structure. Lit. M.P.152-153° C. (Brit J. Pharmacol, 10, 73-86 (1955)).

Also prepared according to the method of example I were:

a) 2,2'methylenebis(4-nonylphenol) was prepared in a similar manner byreplacement of the 1,1,3,3,-Tetramethylbutylphenol by 4-nonylphenol inthe same mole ratio to formaldehyde.

b) 2,2'methylenebis(4-dodecylphenol) was prepared by replacing1,1,3,3-Tetramethylbutylphenol with 4-dodecylphenol at the same moleratio.

c) 2,2'methylenebis 4,6-di(1,1-dimethylpropyl) phenol! was prepared byreplacing 1,1,3,3-Tetramethylbutylphenol with2,4-di(1,1-dimethylpropyl)phenol at the same mole ratio. (see U.S. Pat.No. 2,675,366).

EXAMPLE II

Preparation of 2,2'methylenebis4-(1,1,3,3-tetramethylbutyl)phenol!ethoxylate:

Potassium hydroxide flakes (0.545 g) were added to a melted methylenebisoctylphenol (436 g) in a tarred beaker under nitrogen. Once the KOHwas dissolved in it the solution was carefully poured into a preheated7.57 (2 gallon) reactor. The reactor was degassed by pulling vacuumreleasing with Nitrogen. Ethylene oxide (2-3 moles) was quickly addedallowing for reaction kick. The remaining ethylene oxide (a total of 880g) was added at 150-160° C. and 90 psig max. After 30 minutes thepressure remained constant, the reaction was cooled to 120° C. andvacuum stripped with slight nitrogen sparge for 20 minutes. Finallyacetic acid was added to a pH of 7 to neutralize KOH. Analysis by NMRindicated 20 moles ethylene oxide had reacted. Cloud point (1% aqueous)was 68° C.

The following ethoxylates were prepared according to the method ofExample II.

a) 2,2'methylenebis 4-(1,1,3,3-Tetramethylbutyl)phenol! 2EO was preparedin a similar manner except that 2 moles of ethylene oxide was used permole of 2,2'methylenebis(1,1,3,3-Tetramethylbutylphenol). Cloud point 1%aqueous <0° C.

b) 2,2'methylenebis 4-(1,1,3,3-Tetramethylbutyl)phenol! 18 EO wasprepared in a similar manner except that 18 moles of ethylene oxide wasused per mole methylenebis(octylphenol) in Example II. Cloud point 1%aqueous 64° C.

c) 2,2'methylenebis 4-(1,1,3,3-Tetramethylbutyl)phenol! 10 EO wasprepared in a similar manner except that 10 moles of ethylene oxide wasused per mole of methylenebis(octylphenol). Cloud point 1% aqueous 6° C.

d) 2,2'methylenebis 4,6-di(1,1-dimethylpropyl)phenol! 16 EO was preparedin a similar manner except that 16 moles of ethylene oxide and2,2'methylenebis 4,6-di(1,1-dimethylpropyl)phenol! was used instead of2,2'methylenebis 4-(1,1,3,3-Tetramethylbutyl)phenol!.

e) 2,2'methylenebis(4-nonylphenol) 20 EO was prepared in a similarmanner except that methylenebis(nonylphenol) was used instead ofmethylenebis(octylphenol) and 20 moles of ethylene oxide was added permole methylenebis(nonylphenol). Cloud point 1% aqueous 53° C.

EXAMPLE III

PREPARATION OF SULFATE SODIUM SALTS

Gemini sulfate sodium salts were prepared by the following process:

Ethoxylated methylene bis(octylphenol) (10 g. 8.9 mmol) was flushed withargon at 110° C. for 20 minutes. Sulfur trioxide pyridine complexdissolved in Dimethylformamide was added to the solution at 40° C. Aftertemperature was brought up to 70° C., the reaction mixture was stirredfor 8 hours at this temperature. Once TLC indicated that all startingmaterial disappeared, the reaction was slowly poured into ice/Na₂ CO₃water solution. The pH of solution was maintained around 10 during theprocess. The reaction product was extracted twice with n-butanol. Afterevaporation of solvent, ethanol was added to the residue to removeinorganic salts by filtration. After evaporation of alcohol in thefiltrate, the leftover solid was washed with ether twice again. Thefinal pure product was collected by filtration.

The NMR agreed with the structure.

EXAMPLE IV

PREPARATION OF SULFATE AMMONIUM SALTS

Gemini sulfate ammonium salts were prepared by the following process:

Ethoxylated (20EO) methylenebis(octylphenol) (24.85 g.) was bubbled withargon at 120° C. for 30 minutes. After temperature was cooled to 60° C.,dicyandiamide (0.08 g.) was added. Stirring of the mixture was continuedfor another 20 minutes. Sulfamic acid (4.24 g) was added to the mixture.The reaction was stirred at 140° C. for 7 hours. By that time, TLC(chloroform:methanol:water=4:2:trace) showed that the starting materialdisappeared. The reaction was cooled to 70° C. and pH adjusted to 9 byadding a small amount of monoethanolamine. The NMR agreed with thestructure.

EXAMPLE V

PREPARATION OF PHOSPHATE ESTERS

Phosphate Esters salts were prepared by the following procedure:

Methylenebis(octylphenol)sodium phosphate: A solution of Triethylamine(1.43 g, 14.15 mmol), methylene bis(octylphenol) (3.0 g, 7.0 mmol) indry hexane/THF was added dropwise to a solution of phosphorousoxychloride (1.30 mL, 14.15 mmol) in small amount of hexane under argonat -5° C. A white precipitate appeared. After stirring 2.5 hours at 0°C., TLC (CHCl₃ :CH₃ OH=5:1) showed that all starting materialdisappeared, the reaction was stopped by filtered off triethylammoniumchloride salt. The solvent in filtrate was evaporated under reducedpressure.

A solution of NaOH in ice water was added to the filtrate at 0° C. FinalpH of the solution was about 13. The solution was stirred for two hoursbefore it was extracted with n-butanol three times. After evaporatingsolvent, the solid product was washed with hot ethanol to removeinorganic salt. Ethanol was evaporated under reduced pressure, and thesolid was washed with cold acetone again. The final white pure productwas collected by filtration. This material was confirmed by ¹ H-NMR, ¹³C-NMR and P-NMR. The yield of reaction was 90%.

EXAMPLE VI

    ______________________________________    SURFACE ACTIVITIES    ______________________________________    1 #STR4##                                                 Draves                        Prepared                                γcmc       wetting                        by Method                                dyne/                                     CMC         0.1%    a + b         R       M      of Example                                cm   (M)    pC.sub.20                                                 (sec)    ______________________________________     0   C.sub.8 H.sub.17                 Na     III     27.8 7.9 × 10.sup.-5                                            5.8  5.7     2   C.sub.8 H.sub.17                 Na     III     30.0 1.6 × 10.sup.-5                                            6.1  20.6     2   C.sub.8 H.sub.17                 NH.sub.4                        IV      29.8 6.9 × 10.sup.-6                                            6.2  30.0    18   C.sub.8 H.sub.17                 Na     III     38.2 5.6 × 10.sup.-6                                            6.3    18   C.sub.8 H.sub.17                 NH.sub.4                        IV      36.0 3.4 × 10.sup.-6                                            6.7    22   C.sub.8 H.sub.17                 NH.sub.4                        IV      39.6 3.2 × 10.sup.-6                                            6.3    ______________________________________     ##STR5##    a + b    R       M          Method                                      δdyne/cm    ______________________________________     0       C.sub.8 H.sub.17                     Na         V     27.6    18       C.sub.8 H.sub.17                     Na         V     29.1    ______________________________________

The above data indicates that increased effectiveness (much lower CMC)and increased efficiency (higher pC₂₀ values) can be obtained by usingthe compounds of the invention.

EXAMPLE VII

IRRITATION

The products of this invention were evaluated for mildness by anIn-Vitro Ocular Irritation (Eytex) study.

Alcohol sulfates and alcohol ether sulfates have eye irritancyproperties which limit their use in personal care applications. Usuallyirritation ameliorating agents are used in combination with sulfates tominimize irritation. Compounds of this invention at 1% level have beenshown to be minimal/mild when tested by the Eytex method.

Eytex Draize Equivalent (EDE)

0-15 Minimal

15-19 Minimal/Mild

19-22 Mild

22-25 Mild/Moderate

25-33 Moderate

    ______________________________________    2 #STR6##    a + b           M      EDE    ______________________________________    2               NH.sub.4                           15.8    13              NH.sub.4                           16.0    0               Na     16.2    ______________________________________

A standard laurylether (IEO) sulfate has a score of 27.1 under the sameconditions.

By virtue of this property the surfactants of the invention can be usedin personal care applications without the need for additional additives.

The above data indicates that increased effectiveness (much lower CMC)and increased efficiency (higher pC₂₀ values) can be obtained by usingthe compounds of the invention.

Thus when the surface properties for the compounds of the invention arecompared to the corresponding conventional surfactants C₁₂ H₂₅ OCH₂ CH₂OSO₃ N_(a) has a cmc=4.8×10⁻ 3. See E. Gotte, 3rd Int. Congr. SurfaceActivity, Cologne, 1, 45 (1960)! such as shown in the Table, the novelcompounds of the invention show two unexpected surface activeproperties; unusually low critical micelle concentration (CMC) and pC₂₀values in aqueous media. These properties are a measure of the tendencyof the surfactant to form micelles and adsorb at the interface, andconsequently, to reduce surface tension respectively. The values shownin the Table demonstrate that the compounds of Example III, IV and V areone to two orders of magnitude (10-100 times) more efficient at reducingsurface tension. For example, the pC₂₀ value for sodium lauryl ether(1EO) sulfate is 3.8. See J. A. Caskey; J. Colloid Interface Sci. 35, 46(1971) and more than one order of magnitude (or >10 times) moreefficient at forming micelles. This unusually high surface activity forthese molecules is a result of their unique structure; the presence oftwo optimally spaced hydrophobic chains and hydrophilic groups. Thismolecular structure provides energetically favorable decreases in thefree energy of adsorption and micellization through favorable distortionof water structure, and, at the same time, providing a "close packed"arrangement at the interface. The ability of the compounds of theinvention to distort the water structure through inhibition ofcrystalline or liquid crystalline phase formation in bulk phase and atthe same time to pack closely on adsorption at the interface is contraryto conventional wisdom. This again demonstrates the uniqueness of themolecular design for these compounds which is very critical to providingunexpected exceptional surface and performance properties.

Because of their unusually high surface activity, coupled with theirhydrotropicity and solubilization properties, compounds of thisinvention will provide exceptionally high performance properties, atvery low concentration, in practical applications such as detergencyemulsification, solubilization, dispersancy, hydrotropicity, foaming andwetting. In addition, due to their extremely low monomer concentrationat use levels, because of their extremely low CMC and pC₂₀ values, useof one to two orders of less amounts of the compounds of the invention(compared to conventional surfactants) can provide extremely low or noirritancy in personal care applications.

The unusually high surface activity of the anionic surface active agentsof the invention make them the surfactants of choice in enhancing thesurface activity of mixtures containing other conventional zwitterionic,amphoteric, nonionic and cationic surfactants. It has been surprisinglyfound that the compounds of the invention can be mixed with cationicsurfactants to form stable blends. This is a significant improvement inthe art of forming the surfactant blends which are normal in commercialproducts.

The properties of enhancement of surface activity, solubilization, andwetting of blends, even when used in small concentrations, can have awide applicability in industrial, personal care, and pharmaceuticalapplications where the use of the compounds of the invention, incombination with other conventional surfactants, can provide improvedperformance blends.

Although the subject invention has been described with respect to apreferred embodiment, it will be readily apparent to those havingordinary skill in the art to which the invention pertains that changesand modifications may be made thereto without departing from the spiritor scope of the subject invention as defined by the appended claims.

What is claimed is:
 1. Bis-alkylphenol ethoxylated gemini surfactantscharacterized as mild and environmentally benign comprising compounds ofthe formula: ##STR7## wherein R independently represents alkyl of from 4to 20 carbon atoms, R₁ independently represents hydrogen and alkyl offrom 4 to about 20 carbon atoms; R₂ independently represents --SO₃ M,--P(O)(OM)₂, --CH₂ COOM, or CH₂ CHOHCH₂ --SO₃ M, wherein M representshydrogen, alkali metal, ammonium or an organic base salt; R₃ representsalkylene of from 1 to 10 carbon atoms or --C(O)--R₄ --C(O)-- wherein R₄represents alkylene of from 1 to about 10 carbon atoms or aryl, EOrepresents ethyleneoxy radicals and wherein "a" and b are numbers offrom 0 to about 100, with the proviso that when R₂ is sulfonate and R₃is alkylene, R₁ represents hydrogen.
 2. The surfactants of claim 1,wherein R independently represents straight or branched alkyl of fromabout 6 to about 10 carbon atoms.
 3. The surfactants of claim 1, whereinR₁ is hydrogen.
 4. The surfactants of claim 1, wherein R₂ is --SO₃ M, or--P(O)(OM)₂.
 5. Surfactants of claim 1, wherein R₃ represents loweralkylene of from 1 to 4 carbon atoms.
 6. The surfactants of claim 1,wherein R₃ represents --C(O)--R₄ --C(O)--.
 7. The surfactants of claim1, wherein R₄ is alkylene.
 8. The surfactants of claim 1, wherein R₄ isphenylene.
 9. The surfactants of claim 1, wherein R₂ is --SO₃ M or--P(O)(OM)₂.
 10. The surfactants of claim 1, wherein said organic basesalt is derived from a base selected from the group consisting ofmonoethanolamine, diethanolamine, triethanolamine, triethylamine,trimethylamine and N-hydroxyethyl morpholine.
 11. The surfactants ofclaim 1, wherein M in Formula I is the alkali metal sodium.
 12. Thesurfactants of claim 1, wherein said surfactant comprises compounds ofthe formula: ##STR8## wherein R₃ is alkylene of from 1 to 10 carbons.13. The surfactants of claim 1, wherein said surfactant comprisescompounds of the formula: ##STR9##
 14. A cleaning composition comprisingan aqueous solution having a cleaningly effective amount of thecomposition of claim 1 dissolved therein.
 15. The cleaning compositionof claim 14, wherein the solution is selected from the group consistingof hair shampoos, baby shampoos, body shampoos, bubble baths, bar soaps,bath gels, hair conditioning gels, skin creams and lotions, skincontacting cosmetics, make up removal creams and lotions, liquiddetergents, dish detergents, liquid soaps, bleach activators and bleachstabilizers.
 16. The surfactants of claim 1 wherein "a" is from 1 to 30.17. The surfactants of claim 1 wherein "a" is from 1 to
 30. 18. Thesurfactants of claim 1 wherein "a" is
 5. 19. The surfactants of claim 1wherein "a" is
 9. 20. The surfactants of claim 1 wherein "a" is
 10. 21.The surfactants of claim 1 wherein "a" is
 11. 22. Bis-alkylphenolethoxylated gemini surfactant characterized as mild and environmentallybenign comprising a compound of the formula: wherein R independentlyrepresents alkyl of about 6 to 10 carbon atoms, R₁ is hydrogen; R₂ is--SO₃ M, or --P(O)(OM)₂, wherein M represents hydrogen, alkali oralkaline earth metal, ammonium or an organic base salt; R₃ representsmethylene, and wherein "a" is number of from 0 to about
 30. 23. Thesurfactants of claim 22 wherein R₂ is --SO₃ M.
 24. The surfactants ofclaim 23 wherein R "a" is
 10. 25. The surfactants of claim 22 wherein R₂is --P(O)(OM)₂.
 26. The surfactants of claim 23 wherein "a" is 10.